qemu: introduce period/quota tuning for emulator

This patch introduces support of setting emulator's period and
quota to limit cpu bandwidth when the vm starts.  Also updates
XML Schema for new entries and docs.

diff --git a/docs/formatdomain.html.in b/docs/formatdomain.html.in
index 42df928a301273afa39ee4327b8d4690ad197b45..5d8f66957a8ff0f5e1f1315595ebb5990d86f97b 100644 (file)
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@@ -388,6 +388,8 @@
     <shares>2048</shares>
     <period>1000000</period>
     <quota>-1</quota>
+    <emulator_period>1000000</period>
+    <emulator_quota>-1</quota>
   </cputune>
   ...
 </domain>
@@ -451,6 +453,28 @@
         <span class="since">Only QEMU driver support since 0.9.4, LXC since
         0.9.10</span>
       </dd>
+
+      <dt><code>emulator_period</code></dt>
+      <dd>
+        The optional <code>emulator_period</code> element specifies the enforcement
+        interval(unit: microseconds). Within <code>emulator_period</code>, emulator
+        threads(those excluding vcpus) of the domain will not be allowed to consume
+        more than <code>emulator_quota</code> worth of runtime. The value should be
+        in range [1000, 1000000]. A period with value 0 means no value.
+        <span class="since">Only QEMU driver support since 0.10.0</span>
+      </dd>
+      <dt><code>emulator_quota</code></dt>
+      <dd>
+        The optional <code>emulator_quota</code> element specifies the maximum
+        allowed bandwidth(unit: microseconds) for domain's emulator threads(those
+        excluding vcpus). A domain with <code>emulator_quota</code> as any negative
+        value indicates that the domain has infinite bandwidth for emulator threads
+        (those excluding vcpus), which means that it is not bandwidth controlled.
+        The value should be in range [1000, 18446744073709551] or less than 0. A
+        quota with value 0 means no value.
+        <span class="since">Only QEMU driver support since 0.10.0</span>
+      </dd>
+
     </dl>
 
 

diff --git a/docs/schemas/domaincommon.rng b/docs/schemas/domaincommon.rng
index f4005c51e26d75b736c351154b0c75fc07ec2f73..145caf78d82805cb2a936edba9972afd2f5f0591 100644 (file)
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@@ -581,6 +581,16 @@
               <ref name="cpuquota"/>
             </element>
           </optional>
+          <optional>
+            <element name="emulator_period">
+              <ref name="cpuperiod"/>
+            </element>
+          </optional>
+          <optional>
+            <element name="emulator_quota">
+              <ref name="cpuquota"/>
+            </element>
+          </optional>
           <zeroOrMore>
             <element name="vcpupin">
               <attribute name="vcpu">

diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c
index 9e97301374c323781bf898570e2bdd6c50a93383..724220576add7fac3a527aa4b81afb398cf4359e 100644 (file)
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@@ -8344,6 +8344,14 @@ static virDomainDefPtr virDomainDefParseXML(virCapsPtr caps,
                          &def->cputune.quota) < 0)
         def->cputune.quota = 0;
 
+    if (virXPathULongLong("string(./cputune/emulator_period[1])", ctxt,
+                          &def->cputune.emulator_period) < 0)
+        def->cputune.emulator_period = 0;
+
+    if (virXPathLongLong("string(./cputune/emulator_quota[1])", ctxt,
+                         &def->cputune.emulator_quota) < 0)
+        def->cputune.emulator_quota = 0;
+
     if ((n = virXPathNodeSet("./cputune/vcpupin", ctxt, &nodes)) < 0) {
         goto error;
     }
@@ -13102,7 +13110,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
 
     if (def->cputune.shares || def->cputune.vcpupin ||
         def->cputune.period || def->cputune.quota ||
-        def->cputune.emulatorpin)
+        def->cputune.emulatorpin ||
+        def->cputune.emulator_period || def->cputune.emulator_quota)
         virBufferAddLit(buf, "  <cputune>\n");
 
     if (def->cputune.shares)
@@ -13114,6 +13123,17 @@ virDomainDefFormatInternal(virDomainDefPtr def,
     if (def->cputune.quota)
         virBufferAsprintf(buf, "    <quota>%lld</quota>\n",
                           def->cputune.quota);
+
+    if (def->cputune.emulator_period)
+        virBufferAsprintf(buf, "    <emulator_period>%llu"
+                          "</emulator_period>\n",
+                          def->cputune.emulator_period);
+
+    if (def->cputune.emulator_quota)
+        virBufferAsprintf(buf, "    <emulator_quota>%lld"
+                          "</emulator_quota>\n",
+                          def->cputune.emulator_quota);
+
     if (def->cputune.vcpupin) {
         for (i = 0; i < def->cputune.nvcpupin; i++) {
             virBufferAsprintf(buf, "    <vcpupin vcpu='%u' ",
@@ -13152,7 +13172,8 @@ virDomainDefFormatInternal(virDomainDefPtr def,
 
     if (def->cputune.shares || def->cputune.vcpupin ||
         def->cputune.period || def->cputune.quota ||
-        def->cputune.emulatorpin)
+        def->cputune.emulatorpin ||
+        def->cputune.emulator_period || def->cputune.emulator_quota)
         virBufferAddLit(buf, "  </cputune>\n");
 
     if (def->numatune.memory.nodemask ||

diff --git a/src/conf/domain_conf.h b/src/conf/domain_conf.h
index 5a02323ea776a03285bcc5169e3d97008a118b8c..0c3824ec7f15d3f4568f82f0db6a1744bf52e2b5 100644 (file)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@@ -1614,6 +1614,8 @@ struct _virDomainDef {
         unsigned long shares;
         unsigned long long period;
         long long quota;
+        unsigned long long emulator_period;
+        long long emulator_quota;
         int nvcpupin;
         virDomainVcpuPinDefPtr *vcpupin;
         virDomainVcpuPinDefPtr emulatorpin;

diff --git a/src/qemu/qemu_cgroup.c b/src/qemu/qemu_cgroup.c
index 2fb29b5f5f0540edb46b085cc1972cda3d2a809b..2237d119e63a726f3fba2678dd68358890e036a4 100644 (file)
--- a/src/qemu/qemu_cgroup.c
+++ b/src/qemu/qemu_cgroup.c
@@ -564,7 +564,7 @@ int qemuSetupCgroupForVcpu(struct qemud_driver *driver, virDomainObjPtr vm)
     }
 
     if (priv->nvcpupids == 0 || priv->vcpupids[0] == vm->pid) {
-        /* If we does not know VCPU<->PID mapping or all vcpus run in the same
+        /* If we don't know VCPU<->PID mapping or all vcpu runs in the same
          * thread, we cannot control each vcpu.
          */
         virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
@@ -631,6 +631,8 @@ int qemuSetupCgroupForEmulator(struct qemud_driver *driver,
     virCgroupPtr cgroup = NULL;
     virCgroupPtr cgroup_emulator = NULL;
     virDomainDefPtr def = vm->def;
+    unsigned long long period = vm->def->cputune.emulator_period;
+    long long quota = vm->def->cputune.emulator_quota;
     int rc, i;
 
     if (driver->cgroup == NULL)
@@ -672,6 +674,13 @@ int qemuSetupCgroupForEmulator(struct qemud_driver *driver,
         qemuSetupCgroupEmulatorPin(cgroup_emulator, def->cputune.emulatorpin) < 0)
         goto cleanup;
 
+    if (period || quota) {
+        if (qemuCgroupControllerActive(driver, VIR_CGROUP_CONTROLLER_CPU)) {
+            if (qemuSetupCgroupVcpuBW(cgroup_emulator, period, quota) < 0)
+                goto cleanup;
+        }
+    }
+
     virCgroupFree(&cgroup_emulator);
     virCgroupFree(&cgroup);
     return 0;